tests: factor the generation of files without the final eol

[Akim Demaille]

If some day we find something more portable than Perl.  E.g., toying with 
truncate, but I don't know about its portability.

commit 94291fc21ee30d31632f982bd90097cf546dc7c0
Author: Akim Demaille <address@hidden>
Date:   Sun Oct 13 09:36:45 2019 +0200

    tests: factor the generation of files without the final eol
    
    AFAICT Autotest 2.69 still does not support AT_DATA without the final
    eol.
    
    * tests/local.at (AT_DATA_NO_FINAL_EOL): New.
    * tests/input.at: Use it.

diff --git a/tests/input.at b/tests/input.at
index f3d1578d..35199d8d 100644
--- a/tests/input.at
+++ b/tests/input.at
@@ -2179,12 +2179,11 @@ AT_CLEANUP
 
 AT_SETUP([[Bad character literals]])
 
-AT_DATA([empty.y],
+AT_DATA_NO_FINAL_EOL([empty.y],
 [[%%
 start: '';
 start: '
-]])
-AT_PERL_REQUIRE([[-e "print 'start: \'';" >> empty.y]])
+start: ']])
 
 AT_BISON_CHECK([-fcaret empty.y], [1], [],
 [[empty.y:2.8-9: warning: empty character literal [-Wother]
@@ -2204,12 +2203,11 @@ empty.y:4.8: warning: empty character literal [-Wother]
       |        ^
 ]])
 
-AT_DATA([two.y],
+AT_DATA_NO_FINAL_EOL([two.y],
 [[%%
 start: 'ab';
 start: 'ab
-]])
-AT_PERL_REQUIRE([[-e "print 'start: \'ab';" >> two.y]])
+start: 'ab]])
 
 AT_BISON_CHECK([two.y], [1], [],
 [[two.y:2.8-11: warning: extra characters in character literal [-Wother]
@@ -2219,12 +2217,11 @@ two.y:4.8-10: error: missing "'" at end of file
 two.y:4.8-10: warning: extra characters in character literal [-Wother]
 ]])
 
-AT_DATA([three.y],
+AT_DATA_NO_FINAL_EOL([three.y],
 [[%%
 start: 'abc';
 start: 'abc
-]])
-AT_PERL_REQUIRE([[-e "print 'start: \'abc';" >> three.y]])
+start: 'abc]])
 
 AT_BISON_CHECK([three.y], [1], [],
 [[three.y:2.8-12: warning: extra characters in character literal [-Wother]
diff --git a/tests/local.at b/tests/local.at
index 12443d44..a753f13f 100644
--- a/tests/local.at
+++ b/tests/local.at
@@ -47,6 +47,21 @@ m4_define([AT_SETUP_STRIP],
 ])
 
 
+# AT_DATA_NO_FINAL_EOL(FILE, CONTENT)
+# -----------------------------------
+# Same as AT_DATA, except that CONTENT has no the final end of line.
+#
+# FIXME: AT_DATA or some variant of AT_DATA may eventually permit
+# the final newline to be omitted.  See the threads starting at
+# <http://lists.gnu.org/archive/html/bison-patches/2009-07/msg00019.html>.
+m4_define([AT_DATA_NO_FINAL_EOL],
+[AT_DATA([$1], [$2
+])
+AT_PERL_REQUIRE([[-pi -e 'chomp if eof' $1]])
+])
+
+
+
 ## ------------- ##
 ## Basic tests.  ##
 ## ------------- ##